Department of Plant Sciences, North Dakota State University, Fargo, ND 58108, USA.
Healthy Processed Foods Research Unit, Western Regional Research Center, USDA-ARS, Albany, CA 94710, USA.
Food Res Int. 2023 Dec;174(Pt 1):113503. doi: 10.1016/j.foodres.2023.113503. Epub 2023 Sep 23.
Wet-heating Maillard reaction (MR) has been applied to improve the function of proteins by conjugating with soluble carbohydrates. However, the impact of soluble solutes particularly in plant protein on the degree of MR and the properties of the corresponding conjugates has yet to be discussed. In this study, high-intensity ultrasound (HIUS) was utilized to pretreat commercial pea protein isolate in order to improve its solubility. Two different fractions including soluble fraction (SUPPI) and whole solution (UPPI) of HIUS treated PPI were conjugated with glucose (G) to prepare SUPPI-G and UPPI-G, respectively, over a course of 24 h wet-heating at 80 °C. Conjugation was confirmed by the degree of glycation, SDS-PAGE, FTIR, and intrinsic fluorescence analysis. Color change and glucose content analysis showed that the degree of MR was greater when using SUPPI rather than UPPI. The solubility of SUPPI-G was further improved by 24 h of MR while it remained unchanged for UPPI-G. The emulsifying activity index and foaming capability of SUPPI-G were similar to those of UPPI-G. Interfacial properties determined by dynamic adsorption and dilatational rheology at both oil-water and air-water interface suggested that insoluble fraction of UPPI is essential to make stable emulsions and foams. In conclusion, the proportion of soluble protein in PPI is critical to its wet-heating MR based conjugation with glucose and the solubility of the conjugates.
湿热美拉德反应（MR）已被应用于通过与可溶性碳水化合物结合来改善蛋白质的功能。然而，可溶性溶质（特别是植物蛋白中的）对 MR 程度和相应结合物性质的影响尚未得到讨论。在本研究中，采用高强度超声（HIUS）预处理商业豌豆分离蛋白以提高其溶解度。HIUS 处理后的 PPI 的两种不同级分，包括可溶性级分（SUPPI）和全溶液级分（UPPI），分别与葡萄糖（G）在 80°C 下 24 小时湿热反应，制备 SUPPI-G 和 UPPI-G。通过糖化程度、SDS-PAGE、FTIR 和内源荧光分析证实了结合。颜色变化和葡萄糖含量分析表明，使用 SUPPI 时 MR 程度更高。SUPPI-G 的溶解度在 24 小时的 MR 后进一步提高，而 UPPI-G 的溶解度保持不变。SUPPI-G 的乳化活性指数和起泡能力与 UPPI-G 相似。通过油水界面和空气水界面的动态吸附和膨胀流变学测定的界面性质表明，UPPI 的不溶性部分对于形成稳定的乳液和泡沫至关重要。总之，PPI 中可溶性蛋白的比例对其与葡萄糖的湿热 MR 基结合以及结合物的溶解度至关重要。
